I have had a couple of different pictures and I don't think it changes overly much. If you have something people consider offensive, that might affect it. The best way to gain followers is to comment on Hubs and participate in the community in some way. Finding a niche and simply being a presence,. People will see your name and then check out what you have written. I have gained several new followers in the last couple of days be being more deliberate about posting answers, comments and (hopefully soon) Hubs.
Hope this helps!